Choose the right variant. Mark ___ never ___ to London.

The sentence requires the present perfect tense to indicate an action that happened at an unspecified time in the past and has relevance to the present. The structure for present perfect with 'never' is 'has/have never + past participle'. Since 'Mark' is singular, 'has' is used. The past participle of 'go' is 'gone'. Therefore, the correct option is 'hasn't been' if the intended meaning is that Mark has never been to London, or 'has never been' if that were an option. Given the choices, 'hasn't been' is the closest to a correct present perfect construction, implying a negative experience. However, if the sentence is meant to be affirmative, and 'has never been' is the intended phrase, then none of the options are perfectly correct. Assuming the question implies a completed action or experience, and considering the options provided, 'hasn't been' is the most grammatically plausible choice for a negative statement about visiting London.

Mark hasn't never been to London.